keep travis to compare with github actions

.travis.yml

@@ -0,0 +1,14 @@
+language: shell
+dist: xenial
+os: linux
+
+jobs:
+  include:
+    -
+      language: node_js
+      node_js:
+        - 6
+      before_script:
+        - npm install -g free-programming-books-lint
+      script:
+        - fpb-lint .